*{
    margin: 0;
    padding: 0;
}

ul{
    list-style: none;
    width: 100%;
    height: 40px;
}

ul li{
    float: left;
    width: 100px;
    height: 40px;
    margin-right: 10px;
    border: 1px red solid;
    background-color: aqua;
    text-align: center;
    line-height: 40px;
}